The present invention relates to an electronic sewing machine, wherein a predetermined stitch pattern is automatically formed through the use of a needle positioning mechanism and a work feed mechanism controlled by digital information stored in a memory means installed within the electronic sewing machine.
A typical control system of the above-mentioned sewing machine is disclosed in John W. Wurst, U.S. Pat. No. 3,855,956 "SEWING MACHINE STITCH PATTERN GENERATION FROM STITCH DATA STORED IN STATIC MEMORY", patented on Dec. 24, 1974.
In this prior art system, digital information related to the positional coordinates for each stitch of a predetermined stitch pattern is stored in a read only memory (throughout the following specification the abbreviation ROM is used as a designation for the read only memory). The digital information stored in the ROM is applied directly to a driving means for controlling movement of a stitch forming instrumentality of the electromic sewing machine. The ROM stores digital information related to plural kinds of stitch patterns, and a desired stitch pattern is selected by an operator through a suitable selection means. The selection operation must be conducted every time to initiate the stitch forming operation in the above-mentioned electronic sewing machine of the prior art. That is, in the prior art electronic sewing machine, only one stitch pattern is formed after selection of a desired stitch pattern. There is a great possiblility that plural kinds of stitch patterns are desired to be continuously formed. In this case, selection commands should be stored in a suitable memory means, to thereby automatically form stitch patterns of different kinds in a sequential fashion.